The teacher's breasts constantly drew attention, causing students to lose focus during class. In secret, her cleavage was dubbed the "Devil's Valley," becoming a major topic across the school. One day, a student staying after class confessed, "I can't study because I keep thinking about your breasts." To everyone's surprise, the teacher offered to help resolve his problem. When word spread, male students began openly sharing their struggles, quickly turning the relationship between teacher and students into a hot subject.